---
name: "fixatan"
section: "3alleg4"
platform: "linux"
package: "allegro4-doc"
version: "2:4.4.3.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/fixatan/3alleg4"
---

# fixatan(3alleg4)

Fixed point inverse tangent lookup table. Allegro game programming library.

## NAME

fixatan - Fixed point inverse tangent lookup table. Allegro game programming library.

## SYNOPSIS

**#include \<allegro.h\>**

**fixed fixatan(fixed x);**

## DESCRIPTION

This function finds the inverse tangent of a value using a lookup table. The input value must be a fixed point radian. The inverse tangent is the value whose tangent is \`x'. Example:

```
   fixed result;
   /* Sets `result' to binary angle 13. */
   result = fixatan(ftofix(0.326));
```

## RETURN VALUE

Returns the inverse tangent of a fixed point value, measured as a fixed point binary format angle.

## SEE ALSO